1. Field
The present disclosure relates to a charger preferred as a vehicle-mounted charger or the like.
2. Related Art
There is a vehicle-mounted charger such that alternating current voltage is generated by an inverter, and direct current voltage for charging a storage battery inside the vehicle is generated by the alternating current voltage being rectified. As is commonly known, an inverter is a circuit wherein direct current voltage is converted into alternating current voltage by a multiple of switching elements carrying out switching operations. As a charger in which this kind of inverter is mounted can regulate output current by controlling the pulse width of a gate signal supplied to each switching element of the inverter, there is an advantage in that the charging current can easily be controlled in accordance with the state of charge of the storage battery.
It may happen that the need arises to stop the charging operation suddenly during charging of a storage battery by a charger in order to prevent, for example, an electrocution accident or the like. Herein, when the charger includes an inverter as power conversion means, the charging operation can be stopped by stopping the output of the inverter.
As existing technology for stopping inverter output, there is technology that utilizes a logic circuit. In the case of this technology, a configuration is such that a gate signal is supplied via, for example, an AND gate to each switching element of the inverter. Further, when a forced stop signal for stopping the output of the inverter is generated, passage of the AND gate by the gate signal is impeded by the forced stop signal, whereby the inverter output is stopped. Hereafter, this technology will be referred to as first existing technology.
As other technology that stops inverter output, there is the technology disclosed in JP-A-2010-284051 (“JP '051”). In JP '051, a gate signal generated by a control circuit is supplied to each switching element of the inverter via a photocoupler. Further, in JP '051, the supply of the gate signal from the control circuit to each switching element of the inverter is interrupted by a power supply that supplies a bias current to a phototransistor of the photocoupler being interrupted in accordance with a forced stop signal, whereby inverter output is stopped. Hereafter, this technology will be referred to as second existing technology.